Chapter 13 MISCELLANEOUS TRAFFIC ITEMS

Transcription

1 Chapter 13 MISCELLANEOUS TRAFFIC ITEMS TABLE OF CONTENTS Page INTRODUCTION Purpose 1.02 Scope 1.03 Chapter Organization 1.04 Glossary SCHOOL CROSSING PROTECTION Responsibility 2.02 Guidelines 2.03 School Safety Patrols 2.04 Crossing Guards 2.05 School Speed Limits 2.06 School Site Plan Review 2.07 Rural School Bus Stops 2.08 School Zone and Crossing Signs REVIEWS AND PERMITS Geometric Review 3.02 Preliminary Layouts 3.03 Evaluation of New Facilities 3.04 Entrance Permits 3.05 Transportation Permits 3.06 Parade Permits ROUTE NUMBERING AND REFERENCE POINT SYSTEM General 4.02 Constitutional Routes 4.03 Legislative Routes 4.04 Names and Designations of Certain Highways 4.05 Interstate Routes 4.06 U.S. Highways 4.07 Trunk Highway Routes 4.08 Turnbacks 4.09 Reference Point System 4.10 Exit Numbers SPECIAL INVESTIGATIONS AND STUDIES Videologging 5.02 Rumble Strips 5.03 Experimental Traffic Control Devices 5.04 Speed Trend Studies 5.05 Plat Review 5.06 Sight Distances at Crossroads 5.07 Railroad Crossing Review 5.08 Advisory Curve Study 13-1

2 Page ENGINEERING AND TRAFFIC INVESTIGATION REQUIREMENTS TO ESTABLISH OR CHANGE REGULATORY SPEED LIMITS REFERENCES LIST OF FIGURES Figure Description Page 13.1 Railroad-Highway Grade Crossing Data Sheet a Railroad-Highway Grade Crossing Data Sheet b Railroad-Highway Grade Crossing Data Sheet (cont.) LIST OF CHARTS AND TABLES Figure Description Page 13.1 Required Design Sight Distances for Combinations of Train and Highway Vehicle Speeds (English) Sight Triangles for Moving Vehicle to Safely Cross at Railroad Crossings Sight Triangles for Departure of Vehicle from Stopped Position INTRODUCTION 13-2

3 Purpose The purpose of this chapter is to present those traffic engineering functions which do not fall within material covered in other chapters SCOPE This chapter includes review procedures, permits and guidelines for conducting specific studies and investigations. Other specialized subjects are also discussed CHAPTER ORGANIZATION This chapter has four major sections; School Crossing Protection, Review and Permits, Route Numbering and Reference Point System and Special Investigations and Studies GLOSSARY Ball Bank Indicator - An instrument used to determine the safe speed that a passenger vehicle can comfortably travel around a curved section of roadway. This instrument typically consists of a steel ball in a sealed curved glass tube filled with an alcohol solution. Commissioner - "Commissioner" means the Commissioner of the Minnesota Department of Transportation. County Highway Engineer- "County Highway Engineer" means a registered professional engineer employed as the County Highway Engineer or the Director of Public Works-County Highway Engineer of each county. County State-Aid Highway - A county state-aid highway which: 1. is projected to carry a relatively heavy traffic volume or is functionally classified as collector or arterial as identified on the county's functional plans as approved by the county board; 2. connects towns, communities, shipping points, and markets within a county or in adjacent counties; or provides access to rural churches, schools, community meeting halls, industrial areas, state institutions, and recreational areas; or serves as a principal rural mail route and school bus route; 3. occurs at reasonable intervals consistent with the density of population; 4. provides an integrated and coordinated highway system affording within practical limits, a state-aid highway network consistent with projected traffic demands. Department - "Department" means the Minnesota Department of Transportation. District State-Aid Engineer - "District State-Aid Engineer" means a registered professional engineer employed as the District State-Aid Engineer. Eighty-Fifth Percentile Speed - The speed at or below which 85 percent of the traffic is moving and normally used as a rule of thumb for establishing numerical speed limits. This can be determined directly from field sheets by counting from the top speed the number of vehicles equaling 15 percent of the total number of vehicles observed. The 85th percentile speed is usually within 2 mph of the upper limit of the pace. Experimental Traffic Control Device - Any device which varies from the specifications set forth in the MN MUTCD. 13-3

4 October 31, 2009 Municipal State-Aid Street - A municipal state-aid street which: 1. is projected to carry a relatively heavier traffic volume or is functionally classified as collector or arterial as identified on the urban municipality's functional plan as approved by the urban municipality's governing body; 2. connects the points of major traffic interest within an urban municipality; 3. provides an integrated street system affording, within practical limits, a state-aid street network consistent with projected traffic demands. Pace - The 10 mph range of speeds containing the largest number of observations. The pace can usually be determined by visual inspection of the vehicle speed data sheet. A normal speed distribution will contain approximately 70 percent of the sample within the pace with 15 percent above and 15 percent below the pace. Railroad - "Railroad" means a common carrier by railroad as defined in United States Code, title 49, section 1, clause (3) of the Interstate Commerce Act. Roadway - "Roadway" means that portion of a highway improved, designed, or ordinarily used for vehicular travel, exclusive of the sidewalk or shoulder. In the event a highway includes two or more separate roadways, the term "roadway" as used herein shall refer to any such roadway separately but not to all such roadways collectively. Rumble Strips - A device used to alert the driver that there is a change of conditions ahead. It may consist of raised strips or sawed grooves in the pavement or some other means of creating a "rumble" effect. Rural Section - "Rural section" is a highway design that has wide rights-of-way, open ditches for drainage, and a clearway of usually 30 feet from the edge of the outside lane. Shoulder - "Shoulder" means that part of the roadway which is contiguous to the regularly traveled portion of the roadway and is on the same level as the roadway. The shoulder may be pavement, gravel, or earth. Sidewalk - "Sidewalk" means that portion of a street between the curb lines, or the lateral lines of a roadway, and the adjacent property lines intended for the use of pedestrians. State-Aid Engineer - "State-Aid Engineer" means a registered engineer employed as the State-Aid Engineer of the Minnesota Department of Transportation. State Traffic Engineer- A registered professional engineer employed as the Director, of the Office of Traffic, Safety, and Technology (OTST) in the Policy Safety & Strategic Initiatives Division of the Minnesota Department of Transportation. Street or Highway - "Street or highway" means the entire width between the boundary lines of any way or place when any part thereof is open to the use of the public, as a matter of right, for the purposes of vehicular traffic Through Highway - "Through highway" means every highway or portion thereof at the entrances to which vehicular traffic from intersecting highways is required by law to stop before entering or crossing the same and when stop signs are erected. Transportation District Engineer - "Transportation District Engineer" means a Transportation District Engineer of the Minnesota Department of Transportation. Trunk Highway Turnback - "Trunk highway turnback" means a former trunk highway or portion of it that has reverted to a county or municipality in accordance with law. Urban District - "Urban district" means the territory contiguous to and including any street which is built up with structures devoted to business, industry, or dwelling houses situated at intervals of less than 100 feet for a distance of one quarter mile or more. M.S , Subd

5 Urban Section - "Urban section" means a roadway design used in urban districts where the right-of-way width is restricted. Because of the restricted right-of-way, there is not enough room for ditches, thus necessitating curbs and gutters. Videologging - A permanent pictorial inventory providing instantaneous photographic references for the inspection of highways and roadside features SCHOOL CROSSING PROTECTION Responsibility The safety of school crossings is the joint responsibility of parents, school administrators, other public officials, and the general public. On Trunk Highways, the Department will install appropriate signs and markings at designated school crossings and may authorize local authorities to install additional devices conforming to approved standards in situations that meet reasonable warrants Guidelines Information on school speed control is available in "A Guide to Establishing Speed Limits in School Zones," issued by the Department School Safety Patrols School Safety Patrols are strongly recommended at all crossings used by grade school students. No other means of protection has been as effective as the School Patrol at crossings used by the younger pupils of the grade schools. However, these patrols have not proven effective for high school or junior high school students. Where a School Safety Patrol is functioning as recommended, normally the only necessary controls are the standard school crossing warning signs and markings Crossing Guards Crossing Guards are effectively used at crossings where the use of a School Safety Patrol is considered impractical. Crossing guards are adults who operate in much the same manner as the school patrol in assisting school children to cross arterial streets safely School Speed Limits School speed zoning will not automatically reduce crash frequency or severity. Improper zoning may actually create a situation favorable to crashes, by increasing the speed differential between vehicles and by causing pedestrians to rely on a posted limit which does not accurately reflect vehicular speeds. Thus, speed zoning must be done with great care. The legislation, MSA , Subd. 5a, granting local officials the authority to establish school zone speed limits was not intended as an endorsement of blanket zoning or maximum reductions. Mn/DOT practice is to use fluorescent yellow-green as the background color on the "SCHOOL" plaque (S4-3) and on the top portion of the "SCHOOL SPEED LIMIT" sign (S5-1). Alternatives such as sidewalk construction, fencing, parking restrictions, crossing guard utilization, stop sign or signal placement, and pedestrian rerouting are virtually always more effective in reducing a pedestrian hazard. A traffic and engineering investigation must be undertaken before a speed zone is implemented and consists of two parts: (1) preparing a school route plan and (2) conducting a school zone hazard evaluation. See "A Guide to Establishing Speed Limits in School Zones". 13-5

6 1. School Route Plan - The main objective of a route plan is to minimize the number of streets crossed and to maximize the safety of crossings and routes used by school children. A school route plan for each school serving elementary and kindergarten students is useful in developing uniformity in the use of school area traffic controls. The plan, developed jointly by the school and traffic officials responsible for school pedestrian safety, consists of a map showing the street system, the school, existing traffic controls, established school routes and established school crossings. 2. School Hazard Evaluation - The hazard evaluation process determines those routes which can be made the most safe with the least cost and are most likely to be used by school children. The school route plan should be re-evaluated whenever changes in traffic or pedestrian patterns occur, when control devices change, or when the route's environment changes School Site Plan Review It is the responsibility of the School District, when planning to build a new school facility or make major changes to an in place facility, to obtain all the necessary permits and approvals. The Minnesota Department of Education Planning Guide requires that the School District contact the District Traffic Engineer for guidance in planning for pedestrian and vehicle movements when Trunk Highways are involved. Other road authorities are to be contacted when their roadway is involved Rural School Bus Stops When requested, the District Traffic Engineer shall review rural school bus stops in accordance with Section 7B- 11 of the Minnesota Manual on Uniform Traffic Control Devices. This section establishes the warrants for placement of the "School Bus Stop Ahead" signs. A record should be kept in the District Traffic Office of the rural school bus stops which are so signed. As part of the record, the District Traffic Engineer should, at approximately two year intervals, check back with residents and/or bus operator that each stop is still being made. When determining the need for the "School Bus Stop Ahead" (S3-1) warning sign where the school bus stop is located on or near a vertical curve with restricted sight distance, the height of eye of the driver is 350 feet and the height of object is 6 inches. Given this criteria, the sign is intended to be used where a school bus, when stopped to pick up or discharge passengers, on the roadway is not visible for a distance of 500 feet in advance of the stop. Where the driver can see the full outline of the bus at least 500 feet in advance of the stop, a sign is not required. At vertical curves, the flashing lights mounted at a height of 8 feet) will appear sooner to give the driver an added safety factor. However, advance warning distance may not be available where the school bus stop is located on or near a horizontal curve with a visibility restriction. The location of the sign should give the driver 9-10 seconds reaction/decision time from the sign to the bus stop location. On those highways, a distance of 850 feet to 1000 feet is advised, with the distance of 1000 feet recommended in the horizontal curve case due to greater difficulty for the driver to track the bus. The advance posting distance for lower speeds may be lower, but should not be less than 500 feet in any case. The 9-10 second reaction/decision time times the 85% speed in feet per second is recommended. When requested, the District Traffic Engineer shall review rural school bus stops to determine if a stop qualifies to be signed "School Bus Loading Area". The following criteria must be satisfied prior to the establishment of a school bus loading area: Children will not cross the roadway, either to be picked up or after disembarking from the bus. Shoulders must be wide enough to accommodate full bus width, plus sufficient space for the passengers to safely stand during loading and unloading. No loading area should be established adjacent to an obstruction; such as guardrail, culvert, mail boxes, etc. No loading area shall be permitted in a turn lane. 13-6

7 Districts, at their discretion, may also require that the loading area be hard-surfaced, in order to prevent shoulder breakup and/or bus traction problems during periods when the ground is soft. The sign "School Bus Stop Ahead" shall not be used in advance of a "School Bus Loading Area" stop. Reference: Minnesota Statute , Subdivision 2(b)(1) School Zone and Crossing Signs The "School" sign (S1-1) may be used in advance of locations where school buildings or grounds are adjacent to the trunk highway. If there is a signed school crossing, the "School" sign shall be used in advance of each approach. The sign shall be a fluorescent yellow-green background color with black legend. The School Crossing sign assembly shall consist of the "School" sign (S1-1) and a supplemental down arrow plaque (S2-P2) mounted directly below the "School" sign. The sign and plaque shall be fluorescent yellow-green background with black legend. The School Crossing sign assemblies shall be mounted as near as possible to the crosswalk. See Figure 7.21 for pavement marking details. The assembly may be used at a signalized intersection with crosswalks but should not be used at "Stop" sign controlled intersections. The mixing of standard yellow and fluorescent yellow-green signs of the same type, within a selected site area, shall be avoided. The preferred practice is not to use the speed advisory plaque with school signs. If a black/yellow speed advisory plaque is determined necessary for use with the "School" sign, then the sign and plaque shall be the yellow background color utilizing the wide angle prismatic retroreflective sheeting (commonly referred to as VIP-see Chapter 6 for specifications) REVIEWS AND PERMITS Geometric Reviews Geometric design is concerned with the visible features of a highway such as pavement width, horizontal and vertical alignment, slopes, channelization, interchanges, etc. The design of these features can significantly affect traffic operation, safety and capacity. In fact, some of the traffic problems existing today are the result of geometric design features which could have been corrected during the design stages if the design had been reviewed from a Traffic Engineering point of view. It is essential to maintain regular and cooperative communication between Traffic and Design personnel. Each group needs and benefits from the knowledge and experience of the other Preliminary Layouts The District Traffic Engineers should review all preliminary layouts to provide early input into the design process Evaluation of New Facilities All newly constructed facilities should be evaluated on a systematic operation basis by District Traffic Engineers to assess their effectiveness in moving traffic safely and efficiently. If the improvement is not working as expected, it is imperative that an evaluation of the reasons for failure be made. Positive and negative feedback based on Traffic Engineering evaluations can be an important contribution toward upgrading design standards and criteria to meet changing conditions. A copy of comments should be sent to the State Traffic Engineer. 13-7

8 Entrance Permits (Minnesota Rules, Chapter 8110) No entrance or driveway from a Trunk Highway to private property may be constructed without permission of the Department. Under normal conditions any necessary entrance facilities are provided by the Department when the highway is constructed or reconstructed. However, property and the type of land use are subject to change. Thus, existing access often must be revised. After a highway has been constructed, no additional entrances shall be constructed, nor shall an existing entrance be changed without the approval of the Transportation District Engineer. It is the responsibility of the Area Maintenance Engineer to investigate all requests for such permits and to recommend proper action to the Transportation District Engineer. Entrance permit application forms are discussed in the Maintenance Manual. Traffic Engineering principles should be applied in the investigation, and the District Traffic Engineer should have direct input. A variance from the standards set forth in Chapter 8110 may be allowed by the Department when the variance will facilitate the safe, efficient use of the property for a lawful purpose and will not interfere with the construction, maintenance or safe and efficient use of the highway and its appurtenances by the public Transportation Permits Permits for the movement of over-size or over-weight loads are issued on the authority of the Transportation District Engineer. This is primarily a maintenance function, but the District Traffic Engineer may assist as necessary. Transportation permit guidelines and forms are contained in the Maintenance Manual Use of Highway Right-of-Way for Special Events Use of the trunk highway right-of-way for activities will not be allowed unless a legitimate public interest is to be served. Use of highway right-of-way not related to construction or maintenance requires that the requester contact the Mn/DOT District Office. Mn/DOT authorization will be granted, through the district permit process, if all pertinent criteria covered in these guidelines are satisfied. The permit shall identify that the sponsor agrees to assume the entire responsibility and liability for all damages or injury to all persons, whether employees or otherwise and to all property, arising out of, resulting from or in any manner connected with the operation of the special event. The sponsor shall agree to defend and indemnify Mn/DOT, its agents and employees from all such claims including, without limiting the generality of the foregoing, claims for which Mn/DOT may be claimed to be liable and legal fees and disbursements paid or incurred to enforce the provisions of this paragraph, and the sponsor shall further agree and pay for such general liability coverage which protects the state as an additional named insured. The permit shall also identify that the sponsor shall be responsible for any damage done to the highway property as a result of the special event, damages payable upon receipt of invoice. If Mn/DOT provides assistance in the form of traffic control devices, signs and/or labor, the requester should be billed for the actual costs incurred by Mn/DOT. For purposes of these guidelines, the use of highway right-of-way is split into four categories: 1. Use of Right-of-Way Involving Road Closure 2. Use of Right-of-Way Involving Traffic Restrictions 3. Use of Right-of-Way Not Involving Traffic Restrictions 4. Signs, Banners, and Decorations 13-8

9 October 31, 2009 Within each of these categories, the categories are subdivided as follows: Freeways - Includes interchange areas on expressways Expressways - Does not include interchange areas High Speed, Two Lane, Two-Way Highways - Speed limit 45 miles per hour or greater: includes segments that may have additional lanes for passing, turning or bypassing and/or short segments of four or more lanes. Low Speed Roads - Speed limit 40 miles per hour or less; generally includes those segments of trunk highways that pass through a city and/or serve a city street-type function and all frontage roads Use of Right-of-Way Involving Road Closure Examples of road closures include parades, races, filming, etc. Freeways, Expressways and High Speed Two Lane Two-Way Highways - Closures should not be allowed. Low Speed Roads - Closures may be allowed at the discretion of the District Office subject to the following criteria: 1. Closures shall not be allowed during peak traffic periods unless authorized by the District Traffic Engineer. 2. If the right-of-way is located within a city, requests shall be made through the offices of or by the city. 3. A plan for traffic control and documentation of the means to implement it should be submitted. An adequate detour route shall be provided. Motorists shall be guided through the detour by signs, traffic control personnel, law enforcement personnel or a combination of the three. Signs, if used, shall be in accordance with the Minnesota Manual on Uniform Traffic Control Devices (MN MUTCD). Detour signing, advance notices and publications are the responsibility of the requester. Mn/DOT should review, comment on, and approve the plan. Upon request, Mn/DOT may provide assistance in the form of traffic control devices, signs and/or labor. The requester should be billed for the actual costs incurred by Mn/DOT. 4. All road closures should be coordinated with the State Patrol and the local law enforcement agency. 5. Adequate traffic control and law enforcement personnel shall be arranged by the requester. 6. Festivals with a long history of occurrence and no traffic mobility or safety problems in the past should be allowed to continue. If a new traffic mobility or safety problem arises, it should immediately be brought to the attention of the event sponsor, local municipality, and enforcement agencies to be addressed. If no solution can be found, the organizations shall jointly agree to revise the location of the festival. 7. Denials of permits for road closures may be appealed to the Commissioner of Transportation by the requester Use of Right-of-Way Involving Traffic Restrictions Examples of this category include races, filming, etc. Freeways - Use of the freeway mainline and the adjacent right-of-way should not be allowed. However, use of a local road overpass or underpass area may be allowed in those cases where there is no significant impact on freeway traffic, subject to the criteria covered under "High Speed Two Lane Two-Way Highways and Low Speed Roads," below. Expressways - Use of right-of-way should not be allowed. However, use may be allowed in those cases where there is a limited impact on traffic, subject to the criteria covered under "High Speed Two Lane Two-Way Highways and Low Speed Roads," below. 13-9

10 High Speed Two Lane Two-Way Highways and Low Speed Roads - Use of right-of-way should not be allowed during peak traffic periods. Limited use is allowed subject to the following criteria: 1. The period of time for which a road is restricted for partial use should not exceed four hours. 2. If the right-of-way is located within a city, requests shall be made through the offices of or by the city. 3. The use of the right-of-way shall not interfere with motorists' safe operation of their vehicles. 4. The use of the right-of-way shall not obstruct sight distance and shall not detract from motorists' view of traffic control devices. 5. A plan for traffic control and documentation of the means to implement it should be submitted. 6. Adequate traffic control and law enforcement personnel shall be arranged by the requester. 7. All traffic restrictions should be coordinated with the State Patrol and the local law enforcement agency Use of Right-of-way Not Involving Traffic Restrictions Examples in this category are parking, booths, sales, etc. Freeways - Use of the freeway mainline and the adjacent right-of-way should not be allowed. However, use of a local road overpass or underpass area may be allowed in those cases where there is no significant impact on freeway traffic, subject to the criteria covered under "Low Speed Roads" below. Expressways and High Speed Two Lane Two-Way Highways - Use of right-of-way should not be allowed. However, use may be allowed in those cases where there is a limited impact on traffic, subject to the criteria covered under "Low Speed Roads" below. Low Speed Roads - Use of right-of-way may be allowed subject to the following criteria: 1. If the right-of-way is located within a city, requests should be made through the offices of or by the city. 2. No advertisements should be permitted on the right-of-way. 3. The use of the right-of-way shall not interfere with motorists' safe operation of their vehicles. 4. The use of the right-of-way shall not obstruct sight distance and shall not detract from motorists' view of traffic control devices. 5. Adequate law enforcement personnel protection shall be arranged by the requester, as necessary. 6. Use of the right-of-way shall not exceed 30 days and similar use should not recur within ten months Signs, Banners, and Decorations Freeways - Signs, banners and decorations should not be allowed on the right-of-way. Expressways, High Speed Two Lane, Two-Way Highways and Low Speed Roads - Directional signs may be allowed at the intersection of the local road leading to the event. Non-directional signs, banners and overhead decorations will be allowed only on low speed roads subject to the following criteria: 1. If the signs, banners or decorations are to be located within a city, the requests should be made through the offices of or by the city. 2. Signs, banners or decorations shall not be attached to any Mn/DOT structure (sign, signal, bridge, etc.). 3. Directional and non-directional signing are the responsibility of the requester. If, upon request, Mn/DOT provides assistance in the form of signs and labor, the requester should be billed for the actual costs to the Department

11 4. The requester for directional signing will be advised that signing must conform to the MN MUTCD or as directed by the District Office. 5. Directional signing shall contain only directional information for the event. 6. Non-directional signs or banners shall not appear to represent or conflict with an official traffic control device in shape, form, color or legend. They should be of a neutral color. 7. Non-directional signs or banners should display only the name of the event and the scheduled time. 8. Signs, banners and decorations shall not obstruct sight distance or detract from motorists' view of traffic control devices. 9. No changeable message signs of the type used for temporary or permanent traffic control shall be permitted for event advertising purposes. 10. The minimum clearance for all signs, banners and decorations spanning a highway should be 22 feet above the roadway and shoulder. 11. Adequate traffic control shall be provided when overhead signs, banners, and decorations are being installed and removed. 12. Non-directional signs, banners, and decorations pertaining to an event shall not be in place longer than two weeks prior to the event and shall be removed within three days after the last day of the event ROUTE NUMBERING AND REFERENCE POINT SYSTEM General Each highway in Minnesota is part of a dual system of numbering. The first part of the system is a Constitutional or Legislative route number and the second part is a route signing number (i.e., U.S. route number, Interstate route number or a Minnesota Trunk Highway number). The total numbering system must be kept in logical order and great care must be exercised in changing or revising any portion of the system. There are certain rules which must be followed and certain committees, both locally and nationally, that must be involved to make the system workable Constitutional Routes The Constitutional amendment adopted in 1920 establishing the Minnesota highway system listed 70 routes that by their very description connected various cities and areas in the state into a highway system. These first 70 routes are known as Constitutional Routes and are numbered These routes are described in Minnesota Statutes and, because of the constitutional nature of their establishment, should be considered unchangeable Legislative Routes Since the original 70 routes were established, many additional routes have been added to the Trunk Highway system through action of the Legislature. These routes, currently numbering over three hundred, are known as Legislative Routes. These routes are modified, revised, changed and added to from time to time by the Legislature, usually on the recommendation of the Department. These routes are described in Minnesota Statutes Any changes proposed by the district in these routes should be coordinated through the Department's Control Section and Route Numbering Committees as established by Department Directives 2-015A and 2-02A, respectively Names and Designation of Certain Highways At various times the Legislature has named and designated portions of certain constitutional and legislative routes. Typical names are the "Capitol Highway," "Floyd B. Olson Memorial Highway," "Yellowstone Trail," etc. Named routes are listed in Minnesota Statutes where the route itself is described and the special conditions for signing each route are set forth

12 Interstate Routes The National System of Interstate Highways was established in 1957 with a numbering system and distinctive markers designed by the American Association of State Highway and Transportation Officials (AASHTO). Eastwest routes have even numbers and north-south routes have odd numbers with the lowest number routes in the west and south. Major routes have one or two digit numbers, and the most important routes have numbers ending with 0 or 5. Special, related three-digit numbers are used to designate spurs and circumferential routes in urban areas. Any proposed revisions to this numbering system must be coordinated through the Route Numbering Committee since approval by a National Committee is required prior to any change in the system U.S. Highways The system of United States Numbered Highways was adopted in 1926 in order to provide a uniform system of numbered highways extending across the nation for the benefit of the interstate traveler. The numbering system and the distinctive markers were developed by AASHTO at the request of the Federal Highway Administration and with the advice of several states. This system is kept current through the coordination of AASHTO and the cooperation of the states. From about 40 routes when the system was established there are now close to 200 U.S. routes in the continental United States. Even numbered routes generally follow an east-west alignment, while odd numbered routes are generally north-south. Any proposed changes to this system must be coordinated through the Route Numbering Committee since the approval of the Executive Board of AASHTO is necessary. The U.S. route system is only a route numbering signing system and is not related to Federal funding Trunk Highway Routes All routes not designated as part of the Interstate or U.S. Route number systems are given a "Minnesota" route number. These numbers are assigned by the Route Numbering committee and all requests for new numbers or changes must be coordinated through that committee Turnbacks As roads are rebuilt or new roads are constructed, certain old routes are turned back to the counties and municipalities. The route is deleted from the Trunk Highway system and is normally assigned a route number by the involved jurisdiction. Funds are available for restoration of the roads that have reverted to county and municipal jurisdiction (see Minnesota Statutes and ). Rules and regulations for implementing a "turnback" are set forth in the current Right-of-Way Manual ( ). Upon completion of a "turnback" all responsibility for providing traffic control devices rests totally with the local jurisdiction Reference Point System Reference posting is a continuous distance reference system which indicates the distance from a known starting point. The purpose of a reference point system on freeways and highways is to provide uniform and accurate reference points for all highway-oriented activities. The actual physical reference points consist of reference post marker plates, installed approximately at either one mile intervals along the roadside, which show the continuous distance along the route. Distance numbering is continuous for each route within the State, except where overlaps occur. Distances are computed from the west State line or the westerly terminus for highways running in a general west-east direction, and from the south State line or the southerly terminus for highways running in a general south-north direction

13 The Trunk Highway Logpoint Listing specified the locations of side roads, bridges, crossroads, culverts and other identifiable physical features to the nearest mile. The Logpoint Listing was developed for the purpose of providing more precise and specific reference to locations between the reference posts. Logpoint systems will be developed for both county and municipal road systems. The Reference Point System and Trunk Highway Logpoint Listing are used to aid the several offices and organizations directly associated with highway maintenance and control. Included in the practical uses of the system are the following: 1. Precise identification of crash locations. 2. Reference for the location of emergency incidents. 3. Reference points for roadway maintenance servicing. 4. Reference points for use in road inventory records. 5. Aid to motorists in estimating their progress Overlapping Routes Mileage numbering should be continuous for each route within the state. On overlapping routes, continuity should be established for only one of the routes in accordance with the Control Section Record. On the route without Reference post continuity, the first Reference post beyond the overlap should indicate the approximate distance traveled from the beginning of the route Divided Highways For divided highways, mileage measurements shall be made on northbound and eastbound roadways. The Reference posts for southbound and westbound roadways shall be set at directly opposite locations Transportation Information System (TIS) Reference posts play a critical role in the TIS, as all road features, inventory items, or crash locations are directly or indirectly referenced to the field Reference post. It is imperative that the post be in place. If replacement is required, it must be done in accordance with location instructions from the Program Management Division, if its previous position cannot be precisely determined. When construction projects or turnbacks affect reference posting on any Trunk Highway, the Transportation Research and Investment Management Division should be contacted as to placement of the required posts. Do not invent a new method, as the True Mileage System of the TIS established adjustment rules and procedures to follow Exit Numbering Exits from Interstate highways in Minnesota are numbered in accordance with Federal Highway Administration requirements which specify a reference post format. Exit numbers are displayed at the top of major guide signs located in advance of an interchange at the exit. The exit number normally utilizes the last reference post number in a decreasing reference post direction from the interchange. When there are multiple exits at an interchange (cloverleaf, for example), or more than one interchange for a given reference post, the first exit number in the increasing reference post direction is given the letter "A" and the second the letter "B". Occasionally, a third exit may occur within the same reference post number assigned to an interchange. In that case, the exit would carry the reference post number followed by the letter "C"

14 October 31, SPECIAL INVESTIGATIONS AND STUDIES Videologging Mn/DOT has been recording images of Minnesota's trunk highway system since the summer of The initial system was a photographic system using a 35mm camera, mounted on a van, triggered to take photographs of the roadway every one-hundredth of a mile. In 1987 the system was improved by capturing images on video disc, and transferring them to an optical disc for viewing on dedicated view stations. Today, the video system is state of the art technology with two Video Image Capturing Systems in digital format. These digital images can be conveniently viewed on personal computers that have access to Mn/DOT's internal network system. Since the photos are taken in both directions, 24,000 miles are being photographed and cataloged in the Department's video library. Video pictures are readily available for road condition studies, sign inventories, rightof- way development surveys, and traffic control device evaluation. They also serve as an accurate record for estimating damages resulting from crashes and natural disasters. Viewing equipment is available in the Central Office as well as all District Offices. Copies of photographs can be obtained for Department use at no charge through the Office of Traffic, Safety and Operations. Construction projects, maintenance or utility work and similar activities frequently offer the opportunity to make a photographic record of good or bad applications of traffic control devices. Therefore, when such situations are encountered and are deemed appropriate for photographic study and use in future analysis or training, the District Traffic Engineer is encouraged to request that the site be videologged. In all cases involving the videologging process, the Pavement Management Engineer, Office of Materials and Road Research should be notified so that duplication of requests is avoided. Public access to the photographs will be balanced with Mn/DOT job requirements. Members of the public may view 35mm photographs, optical discs, or digital imagery with the assistance of Department personnel only. Print copies of the photographs may be purchased. This is the only form of duplication currently available. Uniform access to the videolog/photolog viewing equipment for the general public will be based on equipment and personnel availability through the following methods, which are flexible in unusual circumstances. A member of the general public may come to the Office Traffic, Safety, and Technology (OTST), videolog/photolog viewing room or District Office to view the photographs by appointment with the conditions below. 1. Prior to the review, the OTST Tort Claims Office must be contacted so that a determination can be made as to whether or not the State of Minnesota is involved in any litigation relative to this request. If, as a result of this review, it is judges that the State is involved in the litigation, the interested party must make their request for information to the Attorney General's Office and follow the rules of discovery. 2. One week advance notice to arrange an appointment may be required depending on resources. 3. Appointments should be limited to approximately one hour. To accommodate work flow and public access, individuals will be allowed one appointment per week. 4. Prints of videolog/photolog photographs are available to the public from the OTST for a fee

15 October 31, 2009 Viewing equipment and photographs may be used in court cases. Uniform guidelines for all personnel who must present photos of Minnesota's Trunk Highway System in court are as follows: 1. If the photographs are requested to be shown in court, a subpoena must be issued for the film or disc, viewing equipment and operator. (Print copies of the photographs may be obtained without a subpoena being issued if the State is not involved in the litigation. However, if copies of photographs pertaining to litigation against the State of Minnesota are requested, the request must follow the Rules of Discovery. The request MUST be made to the Attorney General's Office.) 2. The user will be charged for all costs incurred. These costs will include: labor costs (to include travel time) for the personnel, transportation costs, all applicable overhead costs, and $ per day for the equipment usage. 3. If it is requested that the disc or film be shown at a speed equivalent to a highway travel speed, make it clear that it will be an approximation only. 4. The requester should be reminded that the photographs represent the date of filming or recording only Rumble Strips Rumble strips may be used when unusual alertness is required of drivers, and standard traffic control devices such as signs and/or flashers have apparently not proven to give adequate warning. Several strips are placed laterally across the pavement to cause a rumble or bumpy motion that, when traversed by a vehicle, will alert the driver. Typical locations for use of rumble strips are approaches to toll gates and to stop signs hidden by horizontal or vertical curves. Proximity of the rumble strip to the hazard is important. If the rumble strip is located too close to the hazard, sufficient driver reaction time is not given; and if they are located too far away, the driver may not relate the rumble strip to the hazard. Mn/DOT has developed a formal rumble strip layout. See the Mn/DOT Road Design Manual, section Experimental Traffic Control Devices Legal Authority Minnesota Statutes , Subdivision 2, states, "The Commissioner may authorize variations from the manual and specifications for the purpose of investigation and research into the use and development of traffic control devices. When such authorized variation pertains to the regulations of traffic, notice of the intended regulatory purpose shall be published in a qualified newspaper of general circulation in the area where the research is being conducted." Procedures The following procedures shall be followed to obtain approval to use experimental traffic control devices: 1. The District Traffic Engineer or Traffic Research Engineer shall originate the procedure by making a thorough investigation relative to the needs for the experimental device, reasons for choosing it, description of devices and expected results. 2. The originator shall submit the above information to the State Traffic Engineer, Office of Traffic, Safety and Technology (OTST) for review with a request for approval. 3. Upon approval, the State Traffic Engineer, OTST shall draft a Commissioner's Order and shall send a copy to the Transportation District Engineer. 4. The Transportation District Engineer shall arrange for the required legal notice to be published in local newspapers

16 October 31, The District Traffic Engineer shall prepare the appropriate Traffic Control Order covering the experimental devices for the State Traffic Engineer s, OTST signature. 6. The District Traffic Engineer and/or Traffic Research Engineer shall review the site upon installation of the device and shall monitor it periodically to assure safe and efficient operation of the device and to recommend any necessary alterations to the State Traffic Engineer, OTST. 7. Upon termination of the operation or experiment, the originator shall submit a report to the State Traffic Engineer, OTST outlining all aspects of the experiment and evaluating the device, recounting both positive and negative aspects, and including comments and suggestions Speed Trend Studies A speed trend study is a method of determining long or short range changes in motorist's travel speed. The study is a compilation of data collected from individual speed monitoring sessions (sometimes called speed surveys) which are analyzed and evaluated. The results from a speed trend study may identify changes in speeds within a certain area which may be attributable to reconstruction, improved lighting, or other roadway changes. Districts can perform speed trend studies to collect information about road segments where speed may be a concern. Historically, speed trend studies were also performed for the Federal Speed Monitoring Program. This program was developed to establish a valid statistical method of measuring a sample of vehicle speeds on a sample of highways posted at 55 mph and 65 mph with sufficient accuracy to support a determination of compliance by a State's motoring public with the National Maximum Speed Limits. In late 1995, the National Maximum Speed Limit was repealed and the submittance of speed monitoring data to the FHWA was performed on a voluntary basis as determined by each state. In order to provide continuity in Minnesota's speed data, it was decided that the monitoring program would continue. Since there are no longer FHWA guidelines to be followed, the program has been modified to best fit Minnesota's needs Minnesota Speed Monitoring Program Every Federal Fiscal Year (October through September), quarterly and annual speed monitoring reports are prepared by the OTST and submitted to the Federal Highway Administration (FHWA) Division Administrator. The results of this program are used to determine speed trends throughout the United States. Additional reports are sent to the Commissioner, all Mn/DOT districts, the Mn/DOT Library, Department of Public Safety, and the Legislative Reference Library. State roadways are divided into 5 categories. Within each of these categories, the total number of roadway miles determines the number of monitoring sites, which are shown below. Category Number of Monitoring Sites Urban Freeway (60-70 mph) 2 Rural Freeway (70 mph) 7 Rural 2-lane, 2-way Highway (55 mph) 14 Rural Divided Highway (65 mph) 6 Urban Divided Highway (55 mph) 2 31 Total 13-16

17 The 31 sites are located throughout the State and each site will be monitored four times a year, once each quarter. A quarterly monitoring schedule is prepared each year. 1. Speed Monitoring Sessions Speed monitoring sessions are performed to collect vehicle speed data which will be incorporated into the speed monitoring program. Various methods are currently being used for the collection of data. Radar transmission devices, although useful in certain situations, are not used in the speed monitoring program due to manpower requirements. Below is a list of speed data collection devices. a. Weigh-In-Motion (WIM) Stations These devices are located throughout the State and collect a variety of data including the weight and speed of vehicles. The information is collected automatically. b. Automatic Traffic Recorders (ATR) Sites ATRs automatically collect information by means of in-pavement loop detectors. ATRs are located throughout the State and are typically used to determine vehicle counts. A small number of them have been installed to allow the collection of speed data. c. Portable data collection machines with road tubes, in-pavement loop detectors, or portable magnetic sensing devices. This method of data collection requires the placement of a sensing device on the road surface which connects to the data collection machine located off the road. This method is undesirable due to manpower requirements. Data for all WIM and ATR sites is obtained from the Traffic Forecasts and Analysis Section. The districts are not directly responsible for obtaining WIM and ATR data. Each speed monitoring session will place vehicle speeds into speed ranges as follows: Number of vehicles from 00 to 40 mph Number of vehicles from 41 to 45 mph Number of vehicles from 46 to 50 mph Number of vehicles from 51 to 55 mph Number of vehicles from 56 to 60 mph Number of vehicles from 61 to 65 mph Number of vehicles from 66 to 70 mph Number of vehicles from 71 to 75 mph Number of vehicles from 76 to 80 mph Number of vehicles from 81 to 85 mph Number of vehicles from 86 to 100 mph This data is then used for the computation of speed trends for the 5 roadway categories. Errors is vehicle speeds are put into a 110 mph range and should not be used in calculations. 2. Speed Monitoring Session Procedures The following procedures shall be followed in analyzing speed data: a. All sessions will be 24 hours in length to account for varying hourly traffic conditions and to facilitate the scheduling of data collection. b. No monitoring should be performed on holidays or weekends on recreational routes. c. The monitoring schedule for the program shows the month and day of week that each monitoring session is to take place. Due to inclement weather and other factors it is not always possible to meet the requirements of the schedule. In the event that the schedule has to be adjusted and a session performed on a different day, keep in mind that all sessions should be evenly distributed by day of week. Data should not be collected on any monitoring station more than once on any day of the week in any one year